How to make amazake with our koji

Amazake is cooked rice mixed with koji yielding, after a period of fermentation, a naturally sweet aromatic thick beverage. Amazake is great as a wholesome sweetener for cakes, muffins or other desserts. Add a touch of unrefined sea salt and a small piece of any sea vegetable, to boost nutrients, minerals, vitamins, and to enhance Amazake’s flavour. Spirulina, blue green algae, wheat grass, nut- and seed butters, flax, vanilla, cinnamon, coriander, coconut, are just some of the foods you can add to enrich or flavour amazake.

Koji is steamed rice that has been inoculated with a variety of the Aspergillus oryzae mold that is then used to make amazake, miso, sake, vinegar, mirin, and more.

Let grain cool down to 135⁰F. Add koji and stir well. Cover. Insert this pot into the large pot with water (double boiler style) that’s between 135⁰F and 140⁰F. Use a thermometer to be able to control the fermentation process closely. Above 140⁰F the koji will get killed, so that’s a critical temperature to stay below. Slip several flame diffusers under the double boiler, to maintain the water bath at the right temperature on a low flame. This is the trickiest part of it all, but once you have figured out what the right number of diffusers is and the setting of your stove, not much can go wrong. We use a cast iron skillet with two diffusers on the smallest burner turned down to its lowest setting.
When doing this for the first time, start in the morning so you can keep an eye on the temperature. Once you know how to keep the temperature constant (within the range of 125⁰F to 139⁰F), make it in the evening and have a tasty pot of amazake ready for you the next morning.

Check temperature of water bath regularly in the beginning to get the temperature right. You can adjust the temperature by the number of flame diffusers.

Let the mixture sit overnight (8-12 hours). Stir occasionally. Speed up the fermentation to only 2 or 3 hours by running the mixture through a blender first.

Fermentation is done when the slurry smells nice and tastes sweet. Cool it down quickly and consume within a few days or bring to a boil to stop the fermentation process to prevent souring; stir continuously to prevent burning or bring the water in your double boiler up to boiling and give the slurry a few hours to rise to above 200⁰F.

Blend until smooth if desired and pour in a mason jar while boiling hot. (Rinse jar with hot water to prevent the glass from cracking.) Or pour into sturdy plastic containers and freeze.

To make rice milk, blend 2 parts amazake with 1 to 2 parts water depending on desired sweetness and consistency. Strain through cheese cloth for smoothness. Bring to a boil and also bottle hot. Refrigerate when cool.